All,
I’m on Toad 12.10.0.25.
I am logged on to a schema. Then, in the project manager view, I right-click on another schema definition in the same database, I select editor.
I get an edit panel for the schema I already was logged on to. Thinking I clicked the wrong schema, I repeat. And again. Same result.
Restarting Toad solved the issue. Problem does not reproduce.
So this is just to make you aware there’s probably something lurking in there 
Kind regards & have a nice weekend!
Abe Kornelis
Just happened again. I was logged on as IIB_KRG@OMSE12, then opened a session to IIB_KRG@OMSE11, closed that session, then opened and closed a session to IIB_KRG@OMSPRD. The initial session was still open and I tried ((using the project manager view) to open a session as EHDA_KRG@OMSE12, but got no result. Retried, again nothing.
I tried to replay the sequence of events. Unfortunately, it still does not reproduce 
Abe